1. Field of the Invention
The present invention relates to a portable telephone and, more particularly, to an improvement in a speech transmission portion in a portable telephone.
2. Description of the Related Art
As conventional portable telephones, structure presented are of two types, one having an integral casing and the other having two casings of the same configuration which are formed foldable with a hinge portion provided therebetween.
In portable telephones having an integral casing structure, a speech reception portion (receiver) and a speech transmission portion (microphone) are provided at the opposite end portions of the casing. On the other hand, portable telephones having two foldable casings commonly have a speech reception portion provided on one of the casings and a speech transmission portion provided on the other.
With a portable telephone having an integral casing, in particular, because of its small size, when a receiver is brought close to the position of an ear, a microphone will be positioned away from a mouth, making a voice to be transmitted lower in some cases.
In addition, because conventional portable telephones employ a nondirectional microphone, unless the microphone is properly disposed near a mouth, surrounding noise will be input to make a partner of telephone conversation have difficulty in hearing a speaker""s voice.
Therefore, conventionally presented is a telephone having a casing provided with a drawable member (square poll), with one of a receiver and a microphone provided at the member and the other provided at the casing, thereby adjusting a distance between the receiver and the microphone to the positions of an ear and a mouth, as disclosed, for example, in Japanese Patent Laying-Open (Kokai) No. Heisei 6-237288.
According to the above-described conventional technique, however, because of a longitudinal drawable member (i.e. square poll) provided at a casing, the member being drawn might make the entire structure fragile. In addition, the drawn member might be caught by clothes etc., which makes the telephone breakable.
An object of the present invention is to provide, for a portable telephone having an integral casing, a structure which enables efficient input of a voice to be transmitted even when a speech transmission portion is not allowed to be proximate to a mouth, thereby allowing comfortable telephone conversation and which involves less breakage etc.
According to one aspect of the invention, a portable telephone formed of an integral casing, comprises
a speech reception portion provided in proximity to one end portion of the casing, and a speech transmission portion provided in proximity to the other end portion of the casing,
the speech transmission portion including a movable portion having a unidirectional microphone therein which portion is disposed to have an angle adjustable with respect to the casing.
Then, adjusting the angle of a movable portion to face a microphone toward a mouth enables efficient input of a voice to be transmitted to allow comfortable telephone conversation even when the microphone and the mouth are placed a little away from each other.
In addition, because of a structure in which the angle of a movable portion in block form housed in a housing concavity is adjusted, a portable telephone of a structure involving less breakage etc. can be provided as compared with that in which a longitudinal member is drawn.
In the preferred construction, the movable portion is provided turnably in a concavity formed in the casing, and angle adjustment of the movable portion causes the microphone to face toward a speaker""s mouth.
In another preferred construction, with no adjustment made of an angle, the movable portion is disposed to have its outer surface substantially flush with an outer surface of the casing so as to cover the housing concavity.
In another preferred construction, the movable portion is formed to have a section in substantially isosceles triangular form.
In another preferred construction, the movable portion is formed to be spherical.
In another preferred construction, a brake mechanism is provided which brakes a turn of the movable portion at the time of adjustment of the angle of the movable portion.
In another preferred construction, the brake mechanism includes
a plurality of engagement claws formed at fixed spacing in the direction of rotation around the axis at the rotational center provided in the movable portion,
a stopper provided movably in the direction in which the stopper comes close to and goes away from any of the plurality of engagement claws provided on the casing side, and
energizing means for energizing the stopper to the direction of engagement with the engagement claws.
In another preferred construction, the portable telephone further comprises a speech transmission signal turn-on means for detecting an angle adjustment being made of the movable portion whose angle has not been adjusted to turn on a transmission line of a speech transmission signal from the microphone.
In another preferred construction, the portable telephone further comprises off-hook means for detecting an angle adjustment being made of the movable portion whose angle has not been adjusted to connect a radio line off the hook.
In another preferred construction, the portable telephone further comprises mutiing means for suppressing the level of a voice to be transmitted when after an angle adjustment of the movable portion makes a radio line be connected off the hook to start telephone communication, the movable portion is returned to have its angle not adjusted.
In another preferred construction, the portable telephone further comprises a displacement mechanism for displacing the movable portion by a set angle of turn.
In another preferred construction, an operation portion is provided for activating the displacement mechanism to displace the movable portion.
In another preferred construction, the displacement mechanism includes driving means connected to a rotary shaft of the movable portion to turn the movable portion, and control means for controlling a turn of the driving means based on a set value of a set angle.
In another preferred construction, the portable telephone further comprises a displacement mechanism for displacing the movable portion by a set angle of turn, a first operation portion for setting an angle of turn of the movable portion for the displacement mechanism, and a second operation portion for activating the displacement mechanism to displace the movable portion,
the displacement mechanism including driving means connected to a rotary shaft of the movable portion to turn the movable portion, and control means having setting means whose angle of turn is set by the first operation means to control a turn of the driving means based on a set value of the setting means.
According to another aspect of the invention, a portable telephone having a folding casing, wherein
two casings are disposed to open and close with a hinge portion provided therebetween,
a speech reception portion is provided on one casing and a speech transmission portion is provided on the other casing, and
the one casing is turnably pivoted on the hinge portion by means of a rotary shaft which rotates in a backward direction around the axis orthogonal to a rotation axis of the hinge portion.
Other objects, features and advantages of the present invention will become clear from the detailed description given herebelow.